The U.S. Green Building Council (USGBC) operates 10 Leadership in Energy and Environmental Design (LEED) Green Building Rating Systems. Eight of those systems—LEED for New Construction (LEED-NC), LEED for Existing Buildings (LEED-EB), LEED for Commercial Interiors (LEED-CI), LEED for Core & Shell (LEED-CS), LEED for Schools, LEED for Retail-New Construction, LEED for Retail-Commercial Interiors, and LEED for Healthcare—require commissioning. The other two—LEED for Homes and LEED for Neighborhood Development—do not. This article will compare and contrast the eight that do.

With the exception of LEED-EB, which differs substantially from the other programs in its commissioning requirements and, thus, will be discussed separately, seven of the eight programs are based on the original LEED-NC program.

LEED Commissioning Requirements

For LEED-NC, fundamental commissioning is a prerequisite, and an additional point can be obtained for enhanced commissioning.

Fundamental-commissioning requirements. The fundamental-commissioning requirements for the LEED-NC, LEED-CI, LEED-CS, LEED for Schools, LEED for Healthcare, LEED for Retail-New Construction, and LEED for Retail-Commercial Interiors are:

Designate a commissioning authority (CxA) who is independent of the project's design and construction management to lead the commissioning process.

Develop and implement a commissioning plan that describes the equipment, team members, schedule, and commissioning tasks involved in the project.

Document the owner's project requirements (OPRs), and develop a basis of design (BOD). The CxA will review these documents and, if needed, facilitate changes.

Develop commissioning specifications that inform the contractors of their responsibilities, and incorporate those specifications into bid documents.

Verify the installation and performance of the equipment included in the commissioning scope.

Complete a summary commissioning report that includes an issues list, test sheets, and an executive summary.

Return to the site 10 months after project completion, meet with the O&M staff, and conduct a post-occupancy review and plan.

Program differences. There are a few differences among the commissioning requirements of LEED-NC, LEED-CI, LEED-CS, LEED for Schools, LEED for Healthcare, LEED for Retail-New Construction, and LEED for Retail-Commercial Interiors. The fact that the programs are virtually identical is probably the most important thing to remember, although LEED reference guides should be consulted before preparing fees for any such work. The few differences include:

The enhanced-commissioning option of LEED for Healthcare, which is in the public-comment phase and likely to be rolled out this year, is the most notable exception. This is the only program that offers two possible points for enhanced commissioning. The requirements for the first point are identical to the LEED-NC enhanced-commissioning requirements. LEED for Healthcare also offers a second point for envelope commissioning, including wall mockups, envelope design review, and a series of planned and documented field inspections.

All programs allow a "streamlined" commissioning approach, by which a design team may provide commissioning for projects less than 50,000 sq ft.1

LEED-EB

Because it focuses on the achievement of sustainability during operation, rather than construction, LEED-EB varies significantly from the other LEED programs. Because existing-building commissioning takes place in the absence of plans and specifications, a bid process and construction contractors make new-building procedures inapplicable.

Following are LEED-EB commissioning requirements:

Develop a comprehensive building-operation plan (BOP) accurately defining the present-day requirements of the building and its ancillary systems.

Prepare a plan for carrying out the testing of all building systems to confirm correct operation and/or define required remedial work.

Implement and document the tasks in the above plan.

Repair and/or upgrade all systems and components found to be deficient during the commissioning process.

Retest all building components after changes are made to ensure optimal operation.

A five-year plan for the continuous improvement of all aspects of the previously mentioned items may be submitted instead. Document continuous improvement through the five-year period. Implement all low-cost/no-cost items in the first two years of the program.

As OPRs are to the new-building commissioning process, a BOP is the heart of the existing-building commissioning process. A BOP may become apparent largely in the day-to-day operation of a building. However, parts of building operation may have diverged significantly from the design. If they have changed slowly, the O&M staff may barely be aware of the change and/or the effect of the change on the success of the building's mission.

A commissioning plan for an existing building includes on-site monitoring of conditions, rather than the checking of newly installed equipment. In an existing building, a CxA is more likely to be required to make minor repairs over the course of commissioning, while in a new building, a CxA is forbidden to alter newly installed systems. LEED-EB requires a CxA to visually confirm the correct operation of manual and automatic systems at the beginning of the commissioning process. Trendlogs that verify this operation must be provided. Further tests of all aspects of mechanical- and electrical-system operation either can be one-time tests (for new buildings) or tests based on trendlogs showing operation over a few days to a few weeks.

The commissioning process for existing buildings almost certainly will involve operation by the O&M staff. In new buildings, the O&M staff may not be available for much of the commissioning process.

SUMMARY

Eight of the current 10 LEED programs require commissioning as a mandatory prerequisite. Five of these programs—LEED-NC, LEED-EB, LEED-CI, LEED-CS, and LEED for Schools—have similar requirements for fundamental and enhanced commissioning. LEED for Healthcare has similar commissioning requirements, but offers two enhanced-commissioning points for commissioning a building envelope.

LEED for Retail-New Construction and LEED for Retail-Commercial Interiors, which are in pilot or comment phases, parallel the commissioning requirements of the LEED-NC, LEED-CS and LEED-CI programs.

The LEED-EB program differs substantially from the other seven programs in terms of commissioning requirements. It substitutes existing-building goals, minor repairs by the CxA, trendlogging for the OPR, and contractor-executed repairs of new programs.

For all programs, it is advisable to purchase the respective LEED reference guide before making the first commissioning proposal. (These guides are not to be confused with the ratings systems, which are abbreviated greatly and can be downloaded at no cost from the USGBC Website, www.usgbc.org.)

REFERENCE

A member of HPAC Engineering's Editorial Advisory Board, Ronald J. Wilkinson, PE, authored the first U.S. Green Building Council Leadership in Energy and Environmental Design commissioning training program. A regular speaker at the National Conference on Building Commissioning, he commissions buildings for AKF Engineers LLC in New York. He earned a bachelor's degree in mechanical and aerospace engineering from the Illinois Institute of Technology in Chicago and a master's degree in public administration from The Evergreen State College in Olympia, Wash.

Coming Soon: Changes to LEED-EB Program

In 2006, the USGBC conducted comment periods and public voting on a new LEED-EB program, which eventually will replace the current Version 2.0 program. As this article goes to press, LEED for Existing Buildings: Operations and Maintenance (LEED-EB: O&M) has passed public ballot and is being prepared for general use.

The USGBC has indicated that the reference guide, online submittal templates, and registration for the new program will be available in spring 2008. In the meantime, the USGBC recommends that projects be registered under Version 2.0. Projects will be able to switch to the new program for free when it is ready. The ratings systems for the current and new programs can be downloaded at no charge from the USGBC's Website at www.usgbc.org/DisplayPage.aspx?CMSPageID=221.

The energy-efficiency requirements for LEED-EB: O&M have increased significantly. The new program requires an energy audit that meets the requirements of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Level I walk-through assessment. Commissioning requirements are:

Energy & Atmosphere Credit 2.2: Existing Building Commissioning—Implementation (2 points). Requires the implementation of low-cost/no-cost projects from Credit 2.1, including the demonstration of savings from those measures and staff training. Also, the building-operating plan must be updated.

Energy & Atmosphere Credit 2.3: Existing Building Commissioning—Ongoing Commissioning (2 points). Requires a continuous commissioning program with a cycle of less than 24 months. At least half of that work must be completed prior to application for the LEED-EB: O&M program. The building-operating plan must be updated.